Snubber connection



W. D. KAHL., JR., ET AL SNUBBER CONNECTION Dec. 29, 1959 Filed Oct. 7,1958 Affamey United States Patent Gice 2,919,037 Patented Dec. 29, 1959SNUBBER CONNECTION William D. Kahl, Jr., Monongahela, and CharlesSteckle,

Jr., McCandless Township, Allegheny County, Pa., as-

signors to United States Steel Corporation, a corpora-l This inventionrelates to a snubber connection and more particularly to a crane boomsnubber connection which transmits force from the snubber to the boom.In the operation of cranes without boom snubbers, breakage of the cableor tackle when lifting heavy loads causes the boom to recoil and snapback over the crane cab. This may damage the boom or the crane andpossibly injure or kill the crane operator. To prevent this fromhappening, boom snubbers such as shown in Sathre et al. Patent No.2,627,985, dated February l0, 1953, have been provided which permit theboom to be raised or lowered in normal operation but which, in the eventof sudden release of load, prevents the boom from recoiling or snappingback over the crane cab. The boom is a column-like member which isnormally made up of four longitudinal corner angles and diagonallyextending connecting members connected to said corner members at panelpoints. The application of the load from the snubber to the cornerangles in the patent is such that failure of the boom may result due to`buckling of the longitudinal angles at the snubber connection.Strengthening of the longitudinal corner angles at the connection isundesirable due to resultant stress concentrations which will causestructural failures.

It is therefore an object of our invention to provide a snubberconnection which will transmit loads from both snubbers to the panelpoints on crane booms and the like without appreciable strengthening ofany individual section of the boom.

Another object is to provide such a connection which will permit thecrane boom to flex without any restraint from the snubber connection.

These and other objects will be more apparent after referring to thefollowing specification and attached drawings, in which:

Figure l is a View of a crane with our invention incorporated therein;

Figure 2 is an enlarged transverse view of the boom at the snubberconnection;

Figure 3 is a View looking toward the left of Figure 2;

Figure 4 is a top plan View of Figure 3;

Figure 5 is a view taken on the line I-V-IV of Figure 4; and

Figure 6 is an enlarged perspective View of a detail.

Referring more particularly to the drawings, reference numeral 2indicates a crane cab which is mounted on the usual tracks y4. Boom 6 ofthe crane is pivotally mounted to the crane cab 2 by means of a pivotconnection 8. An A-frame 10 is mounted on the cab 2. A pair of snubbers12, such as shown in the above mentioned Sathre patent, extend betweenandare connected to the cab 2 and the boom 6. The upper end of the boom6 is supported by a cable 14 having one end connected to boom `6 at 16and the other end connected to boom 6 at point 18. The cable 14 isthreaded about a sheave 20 mounted on A-frame 10 and passes downwardlyto hoisting drums, not shown. The boom 6 consists of longitudinal cornerangles 22, 24, 26 and 28, diagonally extending angles 30I extendingbetween and connected to angles 22 and 26, diagonally extending angles32 extending between and connected to angles 24 and 28, diagonallyextending angles 34 extending between and fastened to angles 22 and 24and diagonally extending angles 36 extending between and fastened to4angles 26 and 28. The parts of the boom are connected by means ofwelding or riveting. The points of connection of the diagonal memberswith the longitudinal members such as points 318, 4t) and 42 are calledpanel points, The parts sopfar described are conventional. Diaphragms 44and 46 are fastened to the boom at panel points 38 and 42. As shown,each of the diaphragms consists of four angles 4S, 4S, 50 and 50 weldedtogether and to the angles 22, 24, 26 and 21S. A bracket 52 is welded toeach of the angles -22 and 24 adjacent the diaphragm 44. Each of thebrackets 52 has an opening therein for receiving a pin 56. A bracket 58is welded to each of the angles 2-2 and 24 adjacent the diaphragm 46.Each of the brackets 58' has a slotted hole 60 therein lfor receiving apin 62. A sleeve 63 may surround the pin 62 to help keep the pin frombinding. Longitudinal supports 64, each of which consists of a T 66, areconnected to the brackets 52 and 58 by means of the pins 56 and `62, asshown. One end of each snubber12 is connected to one of the supports 64by means of a pivot pin 70. For best results the connection should besuch that the longitudinal axis of the snubber will be in generalalignment with the panel point 40 when the boom 6 is positioned midwayof its working range. Since the pins 62 are free to slide longitudinallyin the slots y60 the boom 6 can flex without restraint from the snubberconnection. It is seen that this connection utilizes the maximum lengthof boom section to resist the snubbing forces and at the same timeovercomes the objections to the strengthening small portions of the boomwhich create harmful stress concentration.

While one embodiment of our invention has been shown and described itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of the following claims.

We claim:

1. In a structure having a column-like member, said column-like memberincluding longitudinal corner members and diagonally extendingconnecting members connected to said corner members at panel points, apair of snubbers each having one end connected to said columnlikemember, and an anchor for the other end of each of said snubbers; theimprovement comprising a pair of diaphragms connected to said cornermembers at spaced panel points, a pair of longitudinal supports oneassociated with each of the corner members facing toward said body, abracket attached to each of the last named corner members adjacent eachof said diaphragms, a connection between each of said brackets and theends of the associated supports, one of said connections for eachsnubber permitting movement between the snubber and corner member, meansconnecting one of said snubbers to one of said supports, and meansconnecting the other of said snubbers to the other of said supports.

2. In a structure having a column-like member, said column-like memberincluding longitudinal corner members and diagonally extendingconnecting members connected to said corner members at panel points, apair of snubbers each having one end connected to said columnlikemember, and an anchor for the other end of each of said snubbers; theimprovement comprising a pair of diaphragrns connected to said cornermembers at spaced panel points, a pair of longitudinal supports oneassociated with each of the corner members facing toward said body, abracket attached to each of the last named corner members adjacent eachof said diaphragms, a pin connection between each of said brackets andthe ends of the associated supports, one of said brackets for each ofsaid supports having a slot therein for receiving its associated pin,means connecting one of said snubbers to one of said supports,v andmeans connecting the other of said snubbers to the other of saidsupports.

3. In a crane having a boom, said boom including four longitudinalcorner members and diagonally extending connecting members connected tosaid corner members at panel points, a body and a pair of boom snubbersextending between said body and said boom intermediate the ends thereof;the improvement comprising a pair of diaphragms connected to said boomvat spaced panel points, a pair of longitudinal supports one associatedwith each of the corner members facing toward said body, a bracketattached to each of the last named corner members adjacent each of saiddiaphragms, a connection between each of said brackets and the ends ofthe associated supports, one of said connections for each snubberpermitting movement between the snubber and corner member, meansconnecting one of said snubbers to one of said supports, and meansconnecting the other of said snubbers to the other of said supports.

4. In a crane having a boom, said boom including four longitudinalcorner members and diagonally extending connecting members connected tosaid corner members at panel points, a cable supported adjacent the freeend of said boom, a body and a pair of boom snubbers extending betweensaid body and said boom intermediate the ends thereof; the improvementcomprising a pair of diaphragms connected to said boom at spaced panelpoints with a panel point between the spaced panel points, each of saiddiaphragms including four angles connected to said corner members, apair of longitudinal supports one associated with each of the cornermembers facing toward said body, a bracket attached to each of the lastnamed corner members adjacent each of said diaphragms, a pin connectionbetween each of said brackets and the ends of the associated supports,one of said brackets for each of said supports having a slot therein forreceiving its associated pin, means connecting one of said snubbers toone of said supports, and means connecting the other of said snubbers tothe other of said supports, the longitudinal axes of said snubbers beingin general alignment with the panel point between the diaphragms.

References Cited' in the ile of this patent UNITED STATES PATENTS2,420,163 Borsini May 6, 1947 2,440,199 Huston Apr. 20, 1948 2,509,686Huston May 30, 1950 2,627,985 Sathre Feb. 10, 1953

